Conventionally, an air mattress such as that disclosed in patent document 1 is known. Patent document 1 discloses a technique in which air bladders corresponding to the thigh area, right and left shoulder area, or buttock area of a person reclining upon a base mat of an air mattress are provided, the supply and release of air to and from these air bladders is controlled by a control device, and the breathing motions of the person lying on the air mattress are assisted.
An example of a mattress used by being laid on a bed is disclosed in patent document 2. Patent document 2 discloses a technique of controlling the pressure of air within the mattress according to the physique, body weight, position, or movements of a bed user.